Problem Statement Objectives Scope of work

2

1.2 Background

This project is done to study a single phase cascaded H-Bridge multilevel inverter for 5-level output. Multilevel inverter is the source of high power, often used in industrial applications and can use either sine waves or modified sine waves. The project involves inverter consists of four H-bridge inverters that are cascaded in arrangement. For a 5-level cascaded H-bridge multilevel inverter, 8 switching devices are needed. For this project pulse width modulation PWM will be used as a control method. MOSFET is used as switches because of low power consumption and dissipation. The main objective is to study the single-phase cascaded multilevel inverter for 5-level.

1.3 Problem Statement

Nowadays, industrial applications shows a significant increase in the usage of high voltage and high power. Implementation of two level inverter is not suitable for high voltage and high power conditions and to overcome this problem multilevel inverter is utilized. This study is motivated by several problems which are the less efficiency, high cost, and high switching losses of other types of inverter. Besides, this project is driven by the high efficiency and low switching losses on multilevel inverter. On the other hand, this project is prompted by the low total harmonic distortion THD of cascaded H bridge multilevel inverter in comparing to other multilevel inverter. 3

1.4 Objectives

Based on the problem statement above, this study is motivated by the following objectives which are: i. To study a single phase cascaded H-bride multilevel inverter. ii. To simulate a proposed topology using MATLABSimulink iii. To implement a hardware for a proposed topology

1.5 Scope of work

A project will cover the scope of implementing hardware on circuit that utilize cascaded H bridge multilevel inverter to convert direct current to alternating current. This project can be divided into several stages or steps. Firstly, this study involve the understanding of various type of inverter and multilevel inverter focusing on the cascaded H bridge multilevel inverter. Besides, before implementing the proposed topology, it is important to study about switching especially the MOSFET as switches. Then, pulse width modulation PWM control method to produce the desired output that is five level output. Secondly, the MOSFET and PWM simulation and coding control are done using MATLAB. Lastly, the implementation of hardware are been tested. The limitations of this project are the hardware implementation of the proposed topology is costly due to complexity in assembling the circuit. Other than that, this project requires a long duration of time due to the time taken in understanding the design of proposed topology and the time taken in learning the simulation using MATLAB. 4

1.6 Report outline